Paul Arthur Crafton, the George Washington University professor charged with several offenses in connection with establishing multiple identities, held a secret security clearance during his 25-year career at the Naval Research Lab in Southwest Washington, Navy officials said yesterday.

It was also learned that fellow members of GW's department of engineering administration censured Crafton in 1975 after questions were raised about his general performance as department chairman and his role in supervising a graduate student's doctoral studies. The full school of engineering and applied science did not support the department's findings, however, and the censure remained an internal matter, university officials said yesterday.

Ensign Dennis Sawyer, a Navy spokesman, said Crafton joined the Naval Research Lab on May 9, 1944, as a mechanical engineer in the electronics division of the Security Systems Branch. For most of his career, he worked on the development of experimental equipment for the Identification Friend or Foe project, known in military jargon as IFF.

IFF equipment enables aircraft equipped with so-called "black boxes" to transmit and receive specially coded radar messages to ships.

Crafton, 59, of Potomac, Md., and a tenured full professor at GW, is charged with theft by deception, forgery and tampering with public records in connection with allegedly holding simultaneous jobs at two Pennsylvania state colleges, where he was known by different names.

According to the Pennsylvania attorney general's office, documents found in an apartment Crafton maintained in Lancaster, Pa., indicated that he had taught at six colleges using assumed names, that he had employed a total of 33 aliases and that he had applied unsuccessfully for teaching posts with at least 20 other schools.

He is being held in the Lancaster County jail under two separate $150,000 bonds. A hearing on the possible reduction of one of the bonds is scheduled today.

According to Navy records, Crafton received a commission in the Naval Reserve as an ensign in August 1944 and was honorably discharged in November 1945. His military service was spent working in the research lab, according to Navy records. "Everything in our records indicates his service was outstanding," said one Navy official.

Days after he joined the lab, military records show Crafton was drafted into the Army where he spent five days as a private. Navy officials speculated that the wartime Army was unaware he was working in the lab and "it probably took five days for them to process him out," Sawyer said.

An Army spokesman said yesterday he has no information about Crafton's Army record because of a fire in St. Louis in 1973 that destroyed Army personnel records.

Navy officials said the only break in Crafton's full-time service at the lab occurred from September 1956 to July 1958 when he assumed part-time duties. The part-time work coincides with Crafton's assumption of a full-time professorship at George Washington University.

In January 1969 Crafton left his $19,700-a-year, GS 14 post at the research lab to take a part-time consulting job at the Naval Air Systems Command in Washington. Navy officials said that the Air Systems Command completes projects begun in the lab.

Sam Rothman, current chairman of the GW engineering administration department, confirmed that Crafton was censured by his colleagues, but refused to discuss the reasons. "That was an internal matter within the department," he said yesterday. "I can't discuss that."

According to Robert C. Waters, a professor in the department of engineering administration, members of that department censured Crafton, but the full faculty of the school of engineering and applied science did not support the move.

The reason for the censure, Waters said, was "the fact he completely managed a student's curriculum and dissertation without any outside participation . . . . He arranged all of the exams and directed the research of this student."

Normally a doctoral candidate would have a number of professors supervising course work and there would be records indicating that.

At the time he was censured, Crafton was chairman of the engineering administration department. After the censure, he was replaced by Rothman.

Harold Bright, the GW provost, said he was told the department had taken some action against Crafton, but he said he was unaware of the date or any of the specifics.

Some time after Crafton was censured, the department passed a rule prohibiting any professor from directing more than two of a doctoral candidate's courses, Waters said.

The student under Crafton's supervision completed the required dissertation in one year, an achievement Rothman said is "very rare."

Rothman signed the student's degree and said he listened to the student's "perfectly acceptable" dissertation defense. He declined to discuss the student's course work.

The censure was not the first or last time university officials would learn of problems with Crafton. In 1972, a doctoral student sent a letter to Harold Leibowitz, dean of the engineering school, and the GW president, complaining about Crafton's inaccessability and unwillingness to schedule examinations. "At times I wondered if the Department of Engineering Administration even existed," wrote the student, Max H. Novinsky.

"The difficulty of getting to the guy to schedule my exams or even approve a dissertation topic messed me up considerably," said Novinksy, 63, of Silver Spring. "I'd say it set me back months."

Almost 10 years later, university officials were told by a legal secretary who said she knew Crafton that he was using at least two aliases.

New details of Crafton's background also came to light yesterday, including the fact his name at birth appears to have been Cohen.

Military records show that Crafton listed his father's name as Hyman Cohen, a Rumanian citizen who was naturalized in 1913 in New York City. His mother, Bella Deutsch Cohen, was an Austrian immigrant. Navy officials said that Crafton may have changed his own name before his 1944 graduation from City College of New York.

It was also learned that Crafton, while using the name Anthony Sampson Williams, apparently took a freshman course in English composition at the University of the District of Columbia last spring, according to university sources. A student identification card bearing Crafton's picture, but the name of Anthony S. Williams, was found by Pennsylvania authorities among Crafton's belongings. University spokesman John Britton said he could not divulge whether the course was attended by the student or if a grade was given.

Also found among Crafton's belongings in Pennsylvania, according to Patrick Boyle, spokesman for the Pennsylvania attorney general's office, were documents that indicate that he worked briefly as an accountant in the Anne Arundel Public School system in January 1979. Superintendent Edward J. Anderson said yesterday that the man now known as Crafton used the name Jonathan D. North and provided credentials from English schools.

"He worked for us very briefly, 10 or 15 days," Anderson said, noting that he was fired within about three weeks because the references he cited could not be checked.